Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
05.Sept. 2012 - 22. Okt. 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: well documented guideline study under GLP
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
yes
Remarks:
rel. humidity was between 65 - 95 % during pretest for several hours. However it does not affect the validity of the study.
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
yes
Remarks:
see above.
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
Name: Initiator 94
Batch: 004IN11
according to certificate of analysis and its addendum of 1. August 2012:
purity: 32% (main component and active species: benzpinakolsilylethers)
further composition: Phosphoric acid tributylester (Tributylphosphat) 19.3%, 1,2-Benzenedicarboxylic acid-di-2-propenylester (Diallylphthalate) 8.7%; Methylbenzene (toluol) 12.9%; Diphenylmethanone (Benzophenon) 12.4 %; 1,1,2,2-Tetraphenylethane-1,2-diol (Benzpinakol) 14.6%

density: 1.13 g/cm3 at 20°C
Production date of batch: 16.05.2011

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories B.V., Postbus 6174, NL-5960 AD Horst, The Netherlands
- Age at study initiation: pre-test: 11-12 weeks, main study: 9-10 weeks
- Housing: groupwise
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +- 2 °C
- Humidity (%): 45 - 65%
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, open
Vehicle:
DMSO
Concentration / amount:
A solubility experiment was performed. The highest test item concentration, which could be technically used was a 10% suspension in dimethylsulfoxide (DMSO). At higher concentrations an applicable formulation of the test item was not achieved, neither by the use of other vehicles nor by using additional methods to formulate the test item, i.e. vortexing, sonicatin or warming to 37 °C.
To determine the highest non-irritant test concentration that at the same time did not sinduce signs of systemic toxicity, a pre-test was performed in two animals. Two mice were treated by a epidermal application to the dorsal surface of the ear one with a test item concentrations of 5 % and the other one with a test item concentration of 10 % once daily on three consecutive days.
On days 2-4 the animal treated with a test item concentration of 5 % developped a slight erythema of the skin of the ear.
The animal treated with 10 % developped a well defined erythema of the ears. On day 4 both animals had slightly scrabby ears. Thus the test item in the main study was assayed ar 2.5 %, 5 % and 10%. The highest concentration was the highest level that could be achieved with an applicable formulation and whilst avoiding systemic toxicity and excessive local skin irritation.
Challengeopen allclose all
Route:
epicutaneous, open
Vehicle:
DMSO
Concentration / amount:
A solubility experiment was performed. The highest test item concentration, which could be technically used was a 10% suspension in dimethylsulfoxide (DMSO). At higher concentrations an applicable formulation of the test item was not achieved, neither by the use of other vehicles nor by using additional methods to formulate the test item, i.e. vortexing, sonicatin or warming to 37 °C.
To determine the highest non-irritant test concentration that at the same time did not sinduce signs of systemic toxicity, a pre-test was performed in two animals. Two mice were treated by a epidermal application to the dorsal surface of the ear one with a test item concentrations of 5 % and the other one with a test item concentration of 10 % once daily on three consecutive days.
On days 2-4 the animal treated with a test item concentration of 5 % developped a slight erythema of the skin of the ear.
The animal treated with 10 % developped a well defined erythema of the ears. On day 4 both animals had slightly scrabby ears. Thus the test item in the main study was assayed ar 2.5 %, 5 % and 10%. The highest concentration was the highest level that could be achieved with an applicable formulation and whilst avoiding systemic toxicity and excessive local skin irritation.
No. of animals per dose:
4
Details on study design:
RANGE FINDING TESTS:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 3 consecutive days
- Test groups: 3
- Control group: 1
- Site: dorsal suface of the ear
- Frequency of applications: once daily
- Duration: 24 hours
- Concentrations: 0, 2.5%, 5% and 10% in 25µl/ear/day

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: five days after inuction exposure
- Exposure period: 5 hours
- Test groups:3
- Control group:1
- Site: injection into the tail vein
- Concentrations: 3H-methyl thymidine 19.7 µCi
Positive control substance(s):
yes

Study design: in vivo (LLNA)

Vehicle:
dimethyl sulphoxide
Concentration:
0, 2.5%, 5%, 10%
No. of animals per dose:
4
Details on study design:
RANGE FINDING TESTS:
A solubility experiment was performed. The highest test item concentration, which could be technically used was a 10% suspension in dimethylsulfoxide (DMSO). At higher concentrations an applicable formulation of the test item was not achieved, neither by the use of other vehicles nor by using additional methods to formulate the test item, i.e. vortexing, sonicatin or warming to 37 °C.
To determine the highest non-irritant test concentration that at the same time did not induce signs of systemic toxicity, a pre-test was performed in two animals. Two mice were treated by an epidermal application to the dorsal surface of the ear one with a test item concentration of 5 % and the other one with a test item concentration of 10 % once daily on three consecutive days.
On days 2-4 the animal treated with a test item concentration of 5 % developed a slight erythema of the skin of the ear.
The animal treated with 10 % developed a well defined erythema of the ears. On day 4 both animals had slightly scrabby ears. Thus the test item in the main study was assayed at 2.5 %, 5 % and 10%. The highest concentration was the highest level that could be achieved with an applicable formulation and whilst avoiding systemic toxicity and excessive local skin irritation.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: local lymphnode assay
- Criteria used to consider a positive response: Incorporation of 3H-methyl thymidine (3HTdR) at least 3-fold greater than in control mice and data should be compatible with a conventional dose response curve.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: 0 % 1.00 2.5 % 0.78 5 % 1.43 10% 2.24
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: 0 % 4871 2.5 % 3784 5 % 6965 10% 10907

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Remarks:
Migrated information
Conclusions:
The test item Initiator 94 was not a skin sensitiser.
Executive summary:

In the sudy the test item Initiator 94 was formulated in DMSO and assessed for its possible skin sensitising potential.

A local lymphnode assay was performed. Concentrations of the test item of 0 %, 2.5%, 5 % and 10 % in 25 µl DMSO/ear/day were applied to the dorsal surface of the ears of groups of 4 female mice. The highest concentration was the highest level that could be achieved with an applicable formulation and whilst avoiding systemic toxicity and excessive local skin irritation as shown by a pre-test.

The animals did not show any signs of systemic toxicity.

On days 2 -4 the animals treated with a test item concentration of 10 % showed an erythema of the ear. Animals treated with lower test item concentrations did not show any signs of local skin irritation.

Five days after the first application 19.7 µCi of 3HTdR were injected into the tail vein of each mouse. The limit of a more than 3 -fold greater incorporation of 3HTdR in the trated animals than in the concurrent controls is not reached. Therefore the test item is considered not to be a skin sensitizer.